Mechanism for synchronizing tandem machines



'4 SheeitS-Sheet 1 W. PECHY Filed Sept. 4, 1935 Aug. 1, 1939.

MECHANISM FOR SYNCHRONIZING TANDEM MACHINES 4 Sheets-Sheet 2 W. PECHY MECHANLSM FOR SYNCHRONIZING TANDEM MACHINES Filed sept. 4, 1955 Aug. 1, 1939.

74K ATTQRNEYS( Patented Aug. 1,1939

UNITED STATES PATENT OFFICE MECHANIS )FOR SYNCHRONIZING T EM MACHINES i1 claims.. (ci. 19a-1oz) The present invention relates to machines which perform work cooperatively and successively in tandem upon sheets of tinplate or the like, and has particular-'reference to the auto- 5 matic synchronizing of these machinesso that the sheets may be transferred from one machine to another and work performed upon them in an uninterrupted flow.

An object of the invention is the provision of an apparatus foi` automatically synchronizing the cooperative action of the feeding mechanism of one machine with the feeding mechanism of another so that there is at all times a receiving `unit of the latter in timed receiving position l5 relative to a discharge unit of the former mechanism.`

Another object ofv theinventin is to provide,

in such tandem machines, an'automatic drive,

such as an overrunning clutch, which permits the operation of one of the `machines independently of the other.

A further object of the invention is to provide I such synchronized vmachines with detecting y means which is sensitive to and is. actuated by small but important mechanical or physical changes, such as wear andtemperature, in the various parts of themachines to thereby control the synchronizing of the mechanism affected by such changes.

- A'further object of the invention is to provide the said synchronizing mechanism with starting and stopping devices actuated by the detecting means.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which,

taken in connection with the accompanying,

discloses. a preferred embodiment' drawings,

thereof.

40 Referring to the drawings:

Figure 1 is a plan view of' a pair of machines with drives and synchronizing mechanism embodying the present invention;

Fig. 2 is aiarger. scale sectional'side view of parts of the machines and synchronizing mech'- anism, the latter being shown in section as indicaued by the une z -2 in Fig'. 1;

Figs` 3 and i are vsectional views' taken at is iournaled inthe discharge end ofa delivery4 in Fig. 2 showing"retard and advance cams associated with the drive mechanism;

Fig.- 751s a sectional elevation taken at 1--1 in Fig. 2 showing a reduction gear drive of the synchrcnizing mechanism; and 5 Fig. .8 is a wiring diagram illustrating the electrical Vhook-up of the various elements embodied in the present disclosure.

To illustrate the operations of a preferred em- I bodiment of the instant invention, a coating ma- 10 chine indicated generally by the letter A is shown in Fig. 1, which applies a fllm of lacquer L or the like substance to metallic sheets fed therethrough. The coated sheets coming from this coating machine are transferred to an end- 15 less carrier rack of a drying ovenv B of well known constructionwlierein the drying of the lacquer is accomplished. A clutch device C and a synchronizing mechanism D, shown intermediate and sidewise of the machines .A and B, 20 provide a flexiblefsynchronizing and automatically `adjustable connection between the tandemV machines.A

Thev operation of these various units will now be described in detail in a sequence of presenta- 25 tion which will rst develop the cooperation of the essential elements of machines A and B, and then proceed to a vfuller consideration of the mechanical operation of clutch device C and synchronizing mechanism D in their relations to 30 machines A and B. This will be followed by a more detailed description of the electrical and mechanical devices included in the mechanisms C and D by reference to the diagram in Fig. 8.

Referring toFig. 1, the coating machine A, Y3s

including a pair of feed chains 2|` for propelling' the sheets S through the coating rolls,Y anda pair of cooperating delivery chains 22' for advancing the'coated sheets'into` the reach of the oven carrier, is driven by amotor or primeiro'v mover-'23 throughxa motor pulley, through a belt 25 and themachine drive pulley 2li.` Y

' The pulley 26- is mounted upon a feed shaft 29, which drives sprockets (not shown) over which the chains 2l are driven, and also drives 45 sprockets (not shown) over which the chains 22 are driven the latter also taking over idler sprockets 3l (Fig. 2) mounted on shaft 32, which table.

The chains 2l receive'ncoated sheets S and feed them to acoating roll 35i whichiapplies a dicated by stipplins. y 5i The coated sheets are then engaged by lugs or feed dogs 36 on the delivery chains 22 and are advanced to the delivery end of the machine A, where they are received or picked up by substantially U-shaped prongs or flights 4| of oven conveyor chains 42. Y

The chains 42 are driven either from the motor 23 or from an oven motor 43 in a manner which will be described later. The oven motor` 43 may be termed an auxiliary motor or mover. Either motor drive revolves an oven drive sprocket 44, mounted on anoven drive shaft 45 having bearings in brackets 46 secured to a. frame 41 of the oven B, a collar 48 pinned to shaft 45, adjacent a bearing 46, preventing endwise movement of the shaft. Conveyor chain sprockets 5| ane keyed to the shaft 45 intermediate of the bearings 46, vwhere they engage and drive the conveyor chains 42. .Conveyor chain sprockets 52 support the conveyor chains adjacent the receiving section of the conveyor and are mbunted on a shaft 53 journaled in bearings 54 and 55 on the oven frame 41. Collars 56 pinned to shaft 53 adjacent bearings 54 and 55 prevent endwise movement of the shaft. Y The sheet holding prongs or nights 4| are of substantially U-shaped or looped construction, one of the ends of the loop being fixed in one of the chains 42 while theother end is secured to the other of the chains 42. The prongs 4| are equally spaced from each other and this construction gives a series of substantially parallel sheet supports which are moved through the oven B at a speed consistent with the adequate drying of the coated surfaces of the sheets. Such an oven, being comparatively long, comprises a great many moving parts, which are subjected to high and changing temperatures producing expansion and contraction of the metal parts and resulting in mechanical maladjustment, in addition to such usual maladjustments as arecaused by wear in sprockets and chain links, twists in shafts, etc.

Any or all of these maladjustments usually occur while the machines are in operation. A disturbance of timed relations then results between the receiving prongs 4| of the oven B, and the delivery lugs 36 of the coating machine A. A suilcient disturbance in timing at these and other points may result in damage to machine elements and articles or sheets operated upon. It is obvious that automatic synchronizing of the receiving prongs 4| with the delivery lugs 36 is highly desirable for the efficient and uninterrupted operation of this tandem hookup and this the instant invention aifords. An exemplary embodiment of such an automatic synchronizing mechanism and clutch device will now be described.

Referring t0 Fig. 1, it will be seen that.

a sprocket 6| is mounted on feed shaft 29, which drives a sprocket 62 through a chain 63 which takes over both sprockets. Sprocket 62 is fixed to a shaft 64 journaled in a bearing 65 formed in a base 66 mounted on a sub-base 61. A bevel gear 68 is pinned to the outer end of the shaft A64 and meshes with a bevel gear 69, keyed to a shaft 1| of the clutch device C (see also Fig. 2).

The oven motor 43 is also connected to the drive clutch device C, a coupling 15 connecting a motor shaft 16 to a worm shaft 11 (see also Figs. 2 and 5). This drive is used on occasions when it is desired to keep thev oven B in opera.- tion while the coating machine A and motor 23 are shut down. Such occasion arises, for instance, when it is desired to make changes on 'extending pawl arm flange 95.

the coating machine A, at which time the coating machine would be stopped and the already coated sheets S would be maintained in motion through the oven B.

The automatic switching from a common drive for both machines, effected by motor 23, to an independent oven drive by motor 43, will now be considered. C,

The shaft 1| is formed integrally .with a plate or pawl arm 8| (Fig. 2) and is journaled in an upper half-bearing 82 formed in a cover 83 (see also Fig. 5), bearing 82 being bolted to a lower half-bearing 84 formed in a clutch housing 85, which is integral with the base 66.

A pawl 88 is pivotally mounted on the pawl arm 8| by a shouldered pivot screw 89, and its free extremity is held, under spring pressure, against the periphery of a single tooth barrel ratchet 9| by a spring 92 set in recesses 93 and 94 formed respectively in the pawl 88 and an outwardly As shown in Fig. 5, the pawl 88 is in driving position, engaging a tooth 96 of the barrel ratchet 9|, through which it drives a shaft 91, keyed to the ratchet 9|. Shaft 91 is journaled at the left extremity (Fig. 2) in a bore 98 of the shaft 1|, and adjacent the right end'of the ratchet, the shaft 91 is journaled in a pair of half bearings. The upper half-bearing |0| is formed in the housing cover v83 and the lower half-bearing |02 in the housing 85.

When the common drive, or coating machine motor 23 is stopped, and the independent or oven motor 43 is started, the pawl 88 no longer impels the ratchet 9|,but remains idle. Worm shaft 11, however, is rotated and, between housing bearings |03 and |04 (see Fig. 5) in which it is journaled, a Worm |05 (see also Fig. 2) is fixed to the shaft and meshes with a worm wheel |06. The Worm Wheel is freely mounted von an extension |01 of the ratchet 9|, and carries a pawl pivotally mounted on a shouldered pivot screw ||2 secured in an extension ||3 of the Worm wheel. The pawl like pawl 88 is held against the ratchet 9|, in this instance, by a spring ||4 (Fig. 5) and engages the tooth 96 to drive shaft 91 while pawl 88 remains idle.

In this pair of machinesv being considered, the moving parts in the coating machine A are few compared with those in the oven B. Therefore the possibilities for maladjustment in the coating machine parts which would' aifect the timing between the lugs 36 and prongs 4| are negligible whereas the great number of parts in the oven conveyer as well as vthe temperature variations affecting those parts give rise to timing maladjustments of frequent and varying degrees. The shaft 91 is the driving shaft for the oven Whether the motor 23 or the motor 43 is operating. It is desirable therefore to attach a synchronizing controlling mechanism to moving parts beginning with shaft 91 and those beyond this point. Description of such controlling mechanism, other than that used in driving will be reserved until later when the combined electrical and mechani- 'with a bearing |26, in which is journaled a trunnion |21 formed in a housing cover |28, bolted to `gear |3| is out integral with the shaft. This gear meshes with a smaller intermediate gear |32,

. formed integrallywith a shaft |33, on which is formed another larger intermediate gear |34. The shaft is journaled at one end in a bearing |35 formedl in the housing |22, and at the other end in a bearing |36 formed in the cover |28. Gear |34 meshes with a small driven gear |4|, formed integrally with a stub shaft |42 which is journaled in the trunnion. |21 and coupled to a long oven drive shaft |43 through a coupling |44. Shaft |43 is an extremely long one, so that a purpose of thegears |3|, |32, |34, |4| is to con siderably increase thespeed of the driven shaft |43 vrelative to the driving shaft 91 and thereby reduce the torque in. the long shaft |43 (see Fig. l), which extends nearly the full length of the oven B to thev place where it is journaled in a bearing |45 of a base |46.

considerably from that of shaft |43 by the gearing `relationshipof bevel gears |5|, |52 and the sprockets |55, 44. The oven drive from this point on to the shaft |53 has already been described.. Synchronism between the initial 'drive elements of the coating machine A and shaft 91 has been shown to be effected through the mechanism of clutch`device C, pawl 88 engaging the ratchet tooth 96 to establish timed relations between Vshafts 1| and 91, whenever the common drive .motor 23 is operating..

Synchronism between shaft 91 and the terminal element shaft 53, however, and between the prongs 4| and the lugs. 36,

requires more delicate automatic adjustment.

This is due, in part, to the already mentioned physical and mechanical variables caused by the long'oven and the high temperatures maintained therein. This, latter synchronismA involves the use of electro-mechanical devices which will now be described.

Referring to Fig. 2, a hub |6| is pinned to the -shaft 91. An advance cam |62, and a "reverse cam |63 are formed integrally with the hub |6|.

, where the flan/ge is secured byV clamps |18l and bolts'l1l9. When the machines are set up, initialv setting of the switches |64, |65 with-respect to switch |13 and detector switch |14; respectively.l The four cams and switches just mentioned cooperate in a manner to be described later.

`Switches |64 and |65 are fastened to the inner,

side of a cylindrical housing |15 (see Figs. 2 and 6),#and a flange, |16 of the housing is seated ina recess |11/ formed in bearing .bracket |24,

their cams |62, |63 is eifectedgby loosening bolts |19'and rotating the cylindrical housing |15 to the desiredpsition, and then reclampingit in that position.v

Illhe synchronizing mechanism ediately as# The soclated with shaft 53 is driven by a large gear |8| (see Figs. 1, 2, 3, 4)A keyed to the shaft 53 (Fig. 4). This gear meshes with a smaller gear |82 formed at one end of a shaft |83, which is journaled in a bearing |84 formed in a plate |85. The plate is pivoted on the reduced extremity of shaft 53 (Fig. 4) and clamped at its ends (see Figs. 1, 2) by clamps |86 and bolts l|81 to a bracket |88 which invturn is bolted to the bearing 55. Adjustment of cams |1|, |12 relative to their switches |13,` |14 is effected by loosening bolts |81, turning plate |85 about its pivot shaft 53` tothe desired position, and retightening theF :.bolts.

Shaft |83 carries holding-on cam |1| and detector cam |12 which are keyed to the shaft. The gear ratio of gears |8| |82 is such that shaft |83 makes one revolution for every two chain prongs 4| which pass over the driven sprockets 52.. Holding-on cam 1| has two rises and detector cam |12 has two drops in every 36|Ldegreessof rotation so that switches |13, |14 lwhich'are mounted on plate are actuated once every 180 degrees of cam rotation, .or `once for each prong 4| which passes over the sprockets 52.

Shaft 91 makes one complete revolution for every prong 4| which passes over the sprockets 52, therefore advance cam |62 and reverse cam |63A havebutione rise in 360 degrees of rotation- All of these cams (|1I, |12, |62, |63) actuate their respective switches once during a predetermined period which, in this case, is limited to the lapse of time between the passage of one'prong 4| and another over the ydriven ovensprockets 52.

When such conditions exist as to warrant an advance in the position of shaft 53 with respect to sha-Aft 91 the switches just mentioned are actuated in a manner to be vlater described to start a reversiblesynchronizing motor |9| (see Fig. 1) which then rotates its shaft |92 in anv advance direction'. A motor sprocket |93 is keyed to the shaft |92 and a chain |94 takes over it'and also over a larger vsprocket |95 pinned to a worm shaft |96 (see Figs. 1, 2, '1) journaled in bearings |91, |98 of the'bracket |25. f

A worm 20| is keyed`to the shaft |96 intermediate the bearings |91, |98 rand meshes with a worm wheel 202 keyed to a reduced extension 203 of the trunnion |21. Rotation of the worm wheelv 202. by the motor |9| thus imparts rotation to theV cover |28 and housing |22.v Such rotation also rotates the axis of shaft |33 about the axis common to shafts 91 and |43 and in this instancef causes an increase .in the rotation of shaft |43 with respect to shaft. 91.

'I'his increase in rotation may also be considered 1 as an increase in the gearing ratio between shafts 91 and |43 as long as motor |9| is operating inv anadvanc'e" direction. This increase in rotation is transmitted lthrough the mechanism already described to shaft 53 to reestablish normal relations with shaft 91. Reversing ofv themotor when conditions warrant a retarding-of shaft 53 with respect to shaft 91 likewise effectsa slowing down of shaft 53 with respect to establish normal-conditions.

The wiring diagram of Fig. 8 willnow b e considered in more detail. W

Electricalenergy is supplied to the various units in any suitable manner, as by two generators. A

-direct current generator 205 is indicated in the upper right-corner of Fig. 8 as a sourcevof elecwith the nvarious control and synchronizing 65 shaft 91 to reytrical energy for the detectingcircuits associatedV wires 230,23|, 232 ,to a single contact relay 233 switches, relays, etc. At the bottom of the diagram, an alternating current generator 206 is symbolized as the source of power for the three motors (2 3, 43, I9I) and some relays.

A three-pole double throw switch 201 on the lower right side permits switching' from the one to the other of motors 23, or 43. The switch is shown open, but when swung over to the right, current ows through generator supply wire's 2| I, 2|2, 2|3 to switch connecting wires 2|4, 2|5, 2|6, thence through the switch' 201 to wires 2|1, 2|0, 2|9 which lead the current to the oven motor 43.

For the sake of brevity in describing the path of this and other alternating current circuits reference is merely made to the current leading or flowing to the energized elements.

If the switch 201 -is thrown to the left, lthe current flows through switch 201 to Wires 22|, 222, 223 and thence to the coater motor 23. lThis connection sets up the operation of both coati.ug machine A and oven B as previously described.

With the two machines thus in operation, and the cams and switches previously referred to in properly adjusted or set condition, the operation of the synchronizing mechanism is as follows:

In normal operation, no synchronizing action is necessary. At such time, current does not ilow through any of the detecting circuits as one or more of the switches I 64, |65, |13, |14 are open. The cams and switches are in normal operating positions in the diagram and taken at a. de

is eiected by energizing the synchronizing motor.

|9| so that it rotates in the direction which will be referred to as an advance direction, and means that it imparts to the long drive shaft |43 a slightly increased speed of rotation which ultimately advances the prongs 4| with respectto lugs 36.

The means for effectingthls advance will now be explained. Cams |62 and 63 (Figs. 2 and 8) rotate in clockwise direction at constant speed, being directly connected to the shaft'91. Cams |1| and |12 lag behind the normal timed relation with cams |62, |63 when the prongs 4| lag behind. vCam |1| engages and opens switch |13 for a short interval once for every prong 4| which passes over shaft 53. Cam |12 engages and opens switch |14 for nearly all of the time switch |13 is closed. Whenthese cams lag behind it is equivcontact 226 to wires 221, 228 which lead to advance switch |64 which is now closed.

The current continues through contact 229 and which is energized, wires 234, 235, 236 completing the circuit back to generator 205.

When relay 233 is thus energized, its contacts at 231 are opened but current from wire 23| ,passes through wire 238 to the contact 239 of normally closedrelay 240, the wires 24|, 242 which conduct the current to a double-contact ad- Vance4 relay 245, which is then energized, the

Y through contact 25| to wire 26|.

wires 246, 241 and 236 completing the circuit back to generator 205. The purpose in opening relay 233 will be explained later.

,The energized relay 245 closes its contacts 25| and 252. Closing of contact 25| shorts the circuit which includes detector switch |14 and advance switch |64. Contacts 25| and 252 are held closed by current'which passes through switch |14 until the high spot on holding-on cam |1| is passed, then holding-0n switch |13 is closed.

The circuit which includes detector switch |14 and advance switch |64 is thus shorted through holding-on switch |13. Current then flows from the source 2 05 through Wires 224, 254 to switch |13, thence through the closed contact 255 through wires 256, 251 to re1ay.245, where it passes This wire is connected to wire 23| which was previously shown to lead to other wires and relay 233, then back to generator 205. It follows that the closing of holding-on switch |13 closes an energizing circuit which includes relays 233, 245, and that this circuit remains closed while cam |1| makes substantially half a revolution, a half-revolution representing the passage of oneprong 4| over shaft 53.

Contact 252 is also closed by relay 245 and thereby closes an advance motor relay circuit in which energy flows from the A. C. generator 206 through wires 2| 263, 264 to the contact 252 and thence through the relay 245-and wire 265 to a motor advance relay 261 which is energized, the circuit being completed by wires 268, 2|3 back to the generator 206.

The relay 261- is an element of a reversing switch system the elements of which are located in a box designated by dot and dash lines and indicated generally by the numeral 21|. Relay 261, being energized closes contacts 212, 213, 214 of the reversing switch, thereby Vestablishing a circuit in which energy passes from the A. C. generator 206 through wires 2||, 2|2, 2|3, then through the connected wires 215, 216, 211, the contacts 212, 213, 214, wires 26|, 202, 203, and motor wires 284, 285, 286 to rvotor |9| which rotates in an advance direction for at least the passage of one prong 4| over shaft 53. It will continue to operate in the same direction, however, until the lag in prongs 4| is taken up because-the energizing of the'relays continues as described until a. normal condition exists and the circuits' opened.

When, due to physical and mechanical maladjustment, the oven prongs 4| are ahead lof the delivery lugs 36, the rotation of the synchronizing motor |3| is reversed from the .advance direction previously mentioned, causing a small degree of retardation in the rotation of the long drive shaft |43, and consequentlyY retarding the prongs 4| relative to lugs 36 to restore them to' timed relation with each other.

. The reversal of motor |9| is eiected in the following manner: With the prongs 4| ahead of the 1ugs`36, the cams |62, |63 would not have reached the normal position shown in the dia' through wires 224, 225 to switch |14, thencel 'through the switch contact 226 and wires 221,

231 to switch |65.. The contact 29| now being closed, the current continues through wires 293, 294, 295 to doublecontact relay 299, which is energized by .the current, the circuit beingcompleted by wires 30|, 241 and 236 back to generator'205.

The energized relay v299 closes lcontacts 303, 304. A holding-on circuit is then established by contact 304 an instant after this preliminary energization of the relay. The holding-on circuit is similar to that previously described for the advance circuit. The holding-on circuit originates at the D. C. generator 205, current passing through wires 224, 254, contact 2550i switch |13wires 256, 31|, relay contact 303, wires 3|2, 294 and 295 to relay 299 which is kept energized, the holding-on circuit being completed I through wires 30|, 241, 236 back to generator 205. Single contact relay 240 is simultaneously energized by the parallel circuit starting at Wire 294, thence through .wire 3|3, relay 290, and wires 3|4, 235, 236.

The functions of single contact relays 233, 240 will here-be explained. It'should be noted here that there is a possibility of both switches |64, |65v being closed at thesame time.

233, 240" are so connected into'the circuit that it would be impossible at such a time for both relays 245, 299 Ato be energized at the saine time. This obviates thepossible danger of trying te energize the synchronizing `motor |9| in both advance and reverse directions at the same time.

` operation of motor |9| in only th reverse direverse relay 240. But as this contact is open in the'emergency condition now being considered, advance relay 245 will not be energized. On

i the other han,`.doublecontact reverse relay 2,99 is energize independently of single contact vrelays it having been previously explained that this relay is energized in parallel with single conl ta'c't relay 240. It is therefore obvious that, under the emergency condition being considered, only the reverse relay 299 will be energized. with relay 299`energized, contacts 303, 304 vare closed. Itwas shown that contact 303 closed a holdig-onoircuit. This circuit will remain) closed for a minimumof. a half `revolution of cam |11, when it will be broken `by the opening of being normally moved in timed relation and havswitirm.`

The einem@ sus of reiay- 29s closesl a .circuit which origis at the A. C. generator 203, electrical energy emanatingirom it through :70

wire 2| l. and progressing through wires233,` 32 I,

` contact 304, relay 299, and wire 322 to reversing j switch relay4 323 which is thus energized, the;v circuit being closed-through wires 324, 2|3 to generator 206. v

The energized relay scribed being merely a preferred embodiment Relays means for restoring said timed relation," and The relays 233, 240' cooperate to permit the 323 vcloses reverslngfeontacts 325, 326, 321 and power-is then transmitted from the A. C. generator 206 through the' with respect-to lugs 36 and the consequent automatic relative .readjustment of the timed relation of these parts.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes maybe made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacricingalljof its material advantageathe form hereinbefore dethereof.

l claim': l. A synchronizing mechanism for tandem macomprising in combination: means for advancing articles in one of said machines, means for advancing articles in another'of said machines, a common driving means for said advancing means comprising a prime mover and gearing connected to both of said machines, electro-mechanical detectors associated with both of said advancing means and at the receiving point of said other machine to detect disturbance o'f timed relation between said advancing means, synchronized means operatively connected to ysaid gearing for driving one of. said advancing means while said prime mover is at rest.

2. A synchronizing mechanism for tandem machines operatingupon articles of manufacture, comprising in combination, means foradvancing articles in one of said machines, means for advancing articles inv another of said machines, 'synchronizing means connecting said advancing means, electro-mechanical detectors associated with both of said advancing means and at the receiving part of said other machine for detecting disturbance of timed relation between said advancing means, said detectors operating iny synchronism with their respective advancing meansv and with each other under normal conditions and adapted to actuate 'said synchronizing means to automatically restore said advancing means to timed relation with each other when said relation is disturbed, common drivingI means for said advancing n'ieans comprising a prime mover and gearing. connected to both of said machines, and means. operatively connected'to said gearing for-driving one of said advancing means while said prime mover is at rest.'4

3. In a synchronizing mechanism gior tandem machines operatingupon articles of manufacture, the combination of a vdelivery mechanism in one of said machines, a receiving vmechanism in another of said machines, said mechanisms ing a common driving means comprlsing a prime mover and gearing connected to both, of said.

mechanisms, electro-mechanical means for main-- bination of a delivery mechanism in one machine, a receiving mechanism in another machine, said delivery mechanism being normally in timed relation with said receiving mechanism to effect transfer of said' sheets from said delivery mechanism to said receiving` mechanism, a detecting device associated with said delivery mechanism, a detecting device associated with said receiving mechanism, said detecting devices cooperating to detect maladjustments in the timed relations between said delivery and receiving mechanisms,

a synchronizing mechanism comprising a reversible electric motor associated with and controlled by said detecting devices, said synchronizing mechanism being in turn associated with said delivery and receiving mechanism to establish synchronism therebetween and set in motion to effect said synchronism by said detecting devices when a said maladjustment is detected by said devices,-common driving means for said delivery and receiving mechanisms comprising a prime mover and gearing connected to both of said mechanisms, and means connected to said gearing for driving said receiving mechanism while said prime mover and said delivery mechanism are at rest.

5. In a synchronizing mechanism for machines operating in succession on metal sheets, the combination of a delivery mechanism in one machine, a receiving mechanism in another machine, feed lugs in said delivery mechanism, receiving prongs in said receiving mechanism, said delivery lugs being normally in timed relation with said receiving prongs to effecttransfer of said sheets from said delivery mechanism to said receiving mechanism, detecting cams and switches associated with said delivery lugs, detecting cams and switches associated with said receiving prongs, said detecting cams and switches cooperating to detect maladjustments in timed relation between said deliverylugs and receiving prongs, a synchronizing mechanism associated with and controlled by said detecting cams and switches, said synchronizing mechanism being in turn associated with said delivery lugs and receiving prongs to establish synchronism therebetween, a

synchronizing motor included in anddriving said synchronizing mechanism, said motor being energized through said detecting switches when a maladjustment is detected, common driving means for said delivery and receiving mechanisms comprising a prime moverV and gearingconnected to both of said mechanisms, and

`means connected to said gearing for driving said receiving mechanism while said prime mover and said delivery mechanism are at rest.

- 6. In a pair of machines operating in tandem upon articles of manufacture, the combination of delivery units associated with the first machine, receiving units associated with the second machine, said delivery and receiving units operating normallyin synchronism with each other to facilitate the transfer of said articles from said delivery units to said receiving units, a common driving means for all of said units comprising a prime mover and gearing connected to all of said units, automatic detecting and synchronizing mechanisms associated with said units and cooperating with said common driving means,

while said machines are in motion, for detecting maladjustments which disturb normal synchronism between said units and for restoring synchronism to said units when said maladjustments occur, and means operatively connected to said gearing for driving said receiving units while said prime mover and said delivery units are at rest.

7. In a pair of machines operating in succession upon articles of manufacture, a common driving means for both machines comprising a prime mover and gearing connected to both of said machines, article conveying means in both machines, electro-mechanical synchronism detector and control units associated with moving parts in both machines, a reversible motor mechanically connected with said gearing to increase or decrease the speed -of the second machine relative to the first during the operation of said machines, said detector and control units automatically cooperating only when the machines are out of 'synchronism to start said motor to increase or decrease the speed of said second machine relative to the first until synchronism of operation is restored, and means operatively connected to said gearing for driving one of said article conveying means while said prime mover is at rest.

8. In a pair of machines operating in succession on articles of manufacture, the combination of a common driving means for both machines comprising a prime mover and `gearing connected to both of said machines, article conveying means in both machines, electro-mechanical synchronism detector and control units associated with said conveying means in both machines, a reversible motor geared with said gearing to change the speed of the second machine relative, to the rst during the operation of said machines, said detector and control units automatically cooperating only ywhen the machines are out of synchronism to start said motor and maintain it in operation in either of its reversible directions while synchronism is disturbed, and to stop said motor when synchronism has been restored, and means operatively connected to said gearing for v driving one of said article conveying means while said-prime mover is at rest.

9. The combination of an oven. a conveyor therein which is4 subjected to changes in dimensions by the Aheat of said oven, a feeding conveyor without the oven and operating to deliver parts to the oven conveyor, a motor for driving said feeding conveyor and the oven conveyor shaft at the delivery end of said oven, an auxiliary motor for driving said shaft, means operatively connected to both of said motors for driving said shaft by the second of said motors while the rst of said motors is at rest, and automatic means foraccelerating and retarding the speed of said shaft at the delivery end of the oven conveyor to synchronize the receiving end of the latter with said feeding conveyor. Y

10. The. combination of an oven, a conveyor therein whichis subjected to changes in dimensions by the heatof said oven, a feeding conveyol` without the oven and operating to deliver parts to the oven conveyor, a motor for, driving said feeding conveyor and the oven conveyor A shaft at the delivery end of said oven, an auxiliary motor for driving said shaft, means operatively connected to both of said motors for driving said shaft by the second of said motors while the first of said motors is at rest, and a reversible motor and automatic means for accelerating and retarding the speed of said shaft at the delivery end of the oven conveyor to synchronize the receiving end of the latter with said feeding conveyor..

11. 'I'he combination of an oven, a conveyor therein which is subjected to changes in dimensoV L Y 9,107,670 7 sionsby the heat of said oven and having prongs thereon, a feeding conveyor without the oven und having lugs thereon'operating to deliver parts to said oven conveyor, a. motor for driving said feeding conveyor and the oven conveyor shaft at the delivery end of said oven, an auxiliary motor for driving said shaft, means operativelyy connected to both of said motors for driving said shaftby the second of said motors, while Y the nm of ma motors n u rest, and automne means for accelerating and retsrding the speed,

of sid shaft at the delivery end o! the oven conve'yor to synchronize the receiving end of the latter with said feedingconveyor und to synchronize the respective operations `of said prongs and lugs.

` WILLIAMPECIHY,v 

